2.2 Circulatory System Flashcards
What is the role of Red blood cells ?
Carry oxygen around the body
What is the structure and function of red blood cells ?
- They have a biconcave (disc) shape that provides a large surface area for the diffusion of oxygen
- They contain haemoglobin which is rich in iron, that carries the oxygen
- Have no nucleus and therefore more space for haemoglobin
What is the structure and function of white blood cells (Phagocytes) ?
- Defence against bacteria
- Engulf and digest pathogens
- Larger than red blood cells and fewer in number
- It has a lobed nucleus
What is the structure of white blood cells ( Lymphocytes) ?
- Defence against disease
- Produce antibodies
- Have a large nucleus
- Larger than red blood cells and fewer in number
What is the structure and function of platelets ?
- Very small cell fragments
- Involved in blood clotting and formation of scabs
- Platelets convert the protein molecules to amino acids
- The fibrin forms a mesh network that traps other blood components
What are the main 2 functions of the circulatory system?
- Transport of substances
- Protection against disease
What is the blood composed of and in what amounts
55% liquid plasma and 45% cells
What are the 5 main components of Blood ?
- Red blood cells
- White blood cells (Phagocytes)
- White blood cells (Lymphocytes)
- Platelets and plasma
What is the function of red blood cells?
- carry oxygen around the body
- contain haemoglobin, rich in iron , that carries oxygen
- have a disc (biconcave) shape that provides a large surface area for diffusion of oxygen
- no nucleus, therefore more space for haemoglobin
What shape are red blood cells and why ?
They have a disc/ biconcave shape that provides a large surface area for the diffusion of oxygen
What is the function of Phagocytes (white blood cells) ?
- Defend against bacteria
- Engulf and digest pathogens
- bigger than red blood cells and fewer in number
- Lobed nucleus
What blood cells have a lobed nucleus?
White blood cells (Phagocytes)
What is the function of Lymphocytes ( white blood cells)
- defence against disease
- produce antibodies
- large nucleus
- larger than red blood cells but fewer in number
What is the structure of Lymphocytes
- large nucleus
-larger than red blood cells but fewer in number
What is the structure of red blood cells
- no nucleus therefore more space for haemoglobin
- disc/biconcave shape that provides a large surface area for diffusion of oxygen
- contain haemoglobin rich in iron that carries the oxygen
What is the structure of Phagocytes?
- lobed nucleus
- Larger than red blood cells but fewer in number
- Engulf and digest pathogens
What is the structure and function of platelets
- very small fragments
- involved in blood clotting and formation of scabs
- convert the protein molecules to amino acids
- The fibrin forms mesh network that traps other blood components
What is the structure of platelets?
Very small fragments
What is the function of platelets ?
- Blood clotting and formation of scabs
- Convert the proteins to amino acids
- the fibrin forms a mesh network that traps other blood components
What do platelets do with protein?
Platelets convert the protein molecules to amino acids
What is the structure and function of plasma?
- it is the liquid part of the blood
- responsible for transport of blood cells, glucose, amino acids, CO², hormones and urea
What is plasma responsible for?
The transport of:
- the blood cells
- glucose
- amino acids
- CO²
- hormones
- urea
What is the structure of plasma?
It is the liquid part of the blood
What happens to red blood cells when placed in water?
- They take in water by osmosis and burst in a process called cell lysis or haemolysis.
- This occurs because the concentration of dissolved materials in the plasma is not stable compared to the surrounding water.
- They take in water by osmosis and burst in a process called cell lysis or haemolysis.
- This occurs because the concentration of dissolved materials in the plasma is not stable compared to the surrounding water.
Define the process that occurs when red blood cells burst in water
- Cell lysis or haemolysis
- This is linked to change in os
What type of solution causes red blood cells to swell and burst?
- Hypotonic solution
- Distilled water is an example of a hypotonic solution
What must be kept at a similar concentration in the plasma of the blood and why ?
- The concentration of dissolved materials in the plasma must be kept stable and at a similar concentration to the blood cells
- This is important because if red blood cells are placed in water they will take in water by osmosis and burst in a process called cell lysis or haemolysis
What is the effect of a hypertonic solution on red blood cells?
Cells shrink and shrivel
-This occurs when cells are placed in a concentrated salt solution
Fill in the blank: The process of red blood cells taking in water by osmosis is called _______.
Haemolysis
What type of solution causes red blood cells to shrink and shrivel?
- Hypertonic solution
- Concentrated salt solution is an example of a Hypertonic solution
What equipment is used to view human blood cells on a prepared blood smear?
- A light microscope
- Focus using the low power objective lens before changing it to the higher power objective lens
- It is necessary to adjust the iris diagram to restrict the light passing through the blood smear so as to view the blood cells which are small in size and faint in colour.
Why is it necessary to adjust the iris diagram when viewing human blood cells on a prepared blood smear ?
It is necessary to adjust the iris diagram to restrict the light passing through the blood smear so as to view the blood cells which are small in size and faint colour
How should the blood smear be prepared?
The blood should be smeared across the slide using the edge of a cover slip at a 30-45° angle
What are the three main regions of a blood smear?
- Body
- Counting area
- Feathered edge
What are the 3 types of blood vessels?
- Arteries
- Veins
- Capillaries
What is the structure and function of arteries?
- Carry blood away from the heart ( usually oxygenated blood) apart from the pulmonary artery which goes to the lungs
- Have thick muscular walls
- Have a small lumen ( passageway for blood)
- They contain blood under high pressure
What is the structure and function of veins ?
- Carry the blood to the heart ( usually de-oxygenated) apart from the pulmonary vein which goes from the lungs to the heart
- Have thin walls
- Have a larger internal lumen
- Contains blood under low pressure
- Have valves to prevent blood flowing backwards
What do veins do?
Veins carry (usually de-oxygenated) blood under low pressure towards the heart with valves that maintain the direction of flow
What is the structure and function of Capillaries?
- Found in the muscles and lungs
- capillary wall is made of a single layer of cell one cell thick
- very low blood pressure
- where gaseous exchange takes place, oxygen diffuses through the capillary wall into the tissues; carbon dioxide diffuses from the tissues into the blood
Where are capillaries found?
In the muscles and lungs
Where gaseous exchange takes place where does oxygen and carbon dioxide diffuse from and to
Oxygen diffuses through the capillary wall into the tissue; carbon dioxide diffuses from the tissues into the blood
What is the structure of an artery?
- thick outer wall
- small lumen
- thick layer of muscles and elastic fibres
What is the structure of a vein
- thin layer of muscle and elastic fibres
- large lumen
- fairly thin outer wall
What is the structure of a capillary
- Very small lumen
-wall made of a single layer of cell
How do arteries, capillaries and veins connect in the human body starting with the heart ?
- the heart pumps blood into the arteries
- arteries carry oxygenated blood away from the heart
- arteries divide into very thin vessels called capillaries
- Capillaries go between cells of the body
- Capillaries join up to make veins
- Veins have valves in them
- Veins carry deoxygenated blood back to the heart
What is the name of the smallest blood vessels ?
Capillaries
What do capillaries take away from the cells ?
Carbon dioxide and waste chemicals like urea
What do capillaries bring to the cells?
Oxygen and food molecules like glucose and amino acids
What do arteries do when they get to an organ
They branch many times into smaller arteries and capillaries
What does the heart muscle need to have a constant supply of and why ?
Oxygen and glucose to respire and produce energy.
This energy is used to contract the muscle cells, causing the heart to beat and pump blood around the body to every other cell
What does the heart need its own supply of and what are they called ?
The heart must have its own supply of blood and blood vessels and these special blood vessels are called coronary arteries. They cover the surface of the heart, ensuring all heart cells are in close contact with a blood supply
What are the special blood vessels called that supply the heart with its own blood supply?
Coronary arteries
What does double circulation mean ?
Double circulation means the blood enters thee heart twice before being pumped around the body.
What are the smaller upper chambers of the heart called ?
Left atrium and right atrium
What are the larger lower chambers of the heart called ?
Ventricles - these are more powerful as they pump blood out of the heart
What does the right hand side receive from the body ?
The right hand side receives deoxygenated blood from the body.
What is the job of the right hand side of the heart ?
- The job of the right hand side of the heart is to pump blood to the lungs to pick up oxygen and get rid of carbon dioxide.
- As the lungs are close by, the pump doesn’t need to be very strong so it has a thin layer of muscle
Why does the right hand side of the heart have a thinner layer of muscle ?
Because it is close to the lungs so the pump doesn’t need to be very strong
What does the left hand side of the heart receive?
The left hand side of the heart receives newly oxygenated blood from the lungs
What does the left hand side of the heart do ?
- It pumps the newly oxygenated blood from the lungs and has to pump it around the rest of the body.
What does the left hand side of the heart need to be more powerful and have a thicker layer of muscle?
- The left hand side has to pump the newly oxygenated blood from the lungs around the rest of the body
- The distances are greater and in the case of the upper body the blood flow is against gravity so the left hand side needs to be more powerful.
What are the 2 upper atria separated by from the 2 lower ventricles
They are separated by valves that prevent the blood from flowing the wrong way/direction.
Blood passes through valves as it exits the heart, why is this ?
These prevent blood flowing back into the heart once it has been pumped around the body
What is the vein returning deoxygenated blood from the body to the heart called ?
Vena cava (literally means great vein)
What is the name of the artery that takes deoxygenated blood from the heart to the lungs ?
Pulmonary artery
What is the name of the vein returning oxygenated blood from the lungs to the heart?
Pulmonary vein
What is the name of the artery that takes oxygenated blood from the heart to the body ?
Aorta
What is the vena cava ?
The vein that takes deoxygenated blood from the body to the heart
What is the pulmonary artery?
The pulmonary artery is the artery that takes deoxygenated blood away from the heart to the lungs
What is the pulmonary vein?
It is the vein that takes/ returns oxygenated blood from the lungs to the heart
What is the aorta ?
The aorta is the artery that takes oxygenated blood from the heart to the body
Which of the 4 hearts chambers would contain deoxygenated blood?
The right atrium and the right ventricle
Which of the 4 hearts chambers would contain oxygenated blood?
Left ventricle and left atrium
Which 2 major veins bring blood back to the heart from the body
- pulmonary artery
- vena cava
What does blood bring to cells ?
Oxygen, glucose and amino acids
What does blood take away from cells ?
Blood takes away waste produced from chemical reactions in cells like carbon dioxide and urea
Where and how does the body get rid of carbon dioxide?
- The carbon dioxide is carried in the plasma where diffusion happens in the lungs.
- The carbon dioxide diffuses into the alveoli where it’s exhaled
Where and how does the body get rid of (excrete) urea?
- The urea is carried in the plasma down to the kidneys.
- The kidneys filter the urea out of the blood to be stored in the bladder as urine and then is passed out
What is the role of the hepatic artery
Carries oxygenated blood away from the heart to the liver
What is the role of the hepatic vein?
Carries deoxygenated blood from the liver to the heart
What is the role of the renal artery ?
Carries oxygenated blood away from the heart to the kidney
What is the role of the renal vein ?
Carries deoxygenated blood from the kidney to the heart
What is the role of the hepatic portal vein ?
Carries deoxygenated blood from the intestine liver
Who has a longer recovery time/rate ?
An unfit person
How does regular exercise benefit the heart ?
- Regular exercise strengthens the heart muscle over a period of time
- so a fit person will pump more blood with each heart beat
